I could not really find anything matching, maysome someone got an idea or a starting point:

I want to maintain a collection of documents written in Kile, Using LaTeX converted by xetex into pdf format. These documents have to be updated from time to time. I required each document to be available in two or three languages.

I do not want to maintain separate source files/collections for the different languages, since this will certainly lead to documents running out of sync. Instead I imagine something like this:

- each token of natural language ("phrase") will be enclosed in a macro
- the macro fetches the translation of the phrase from a local service
- this service could be a script reading translations from a file

Since there are applications suitable to maintain such phrase collections this appears to be a natural approach to me. However, I fail to find a good starting point..